Short-circuiting mechanism



Jan. 8, 1924. 1,480,328

C. H. WOLFF SHORT CIRCUITING MECHANISM Filed Jan. 19, 1923 2 Sheets-Sheet 1 l myENToR V Jan. 8,71924. 1,480,328

c. H. woLFF SHORT CIRCUITING MECHANI SM Filed dan. 19, '1925 2 sheets-sheet z m MIMNVENTDR. YgQ/MW ATTORNEY Patented Jan. 8, 1924.

UNITED STATES PATENT oEFlcE.

CARL H. WOLFF, OF ST; LOUIS, MISSOURI, ASSIGNOR TO' WAGNER ELECTRIC CORPORA- TION, OF ST. LOUIS, MISSOURI, A CORPORATION 0F DELAWARE.

SHORT-CIRCUITING HECHANISM.

appuoauon mea January 19, 1923. serial No. 613,629.

To all whom it may concern:

Be it known that I, CARL H. VVoLlna",` a citizen of the United States of America, residing at the city of St. Louis, State of Missouri, vUnited States of America, have invented a` certain new and useful Short-- Gircuiting Mechanism, of which the following is such a full, clear, and exact description as will enable anyone skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to means for reorganizing the winding circuits of an A. C. motor through the agency of centrifu l mechanism, a specihc apphcation bein or the purpose of shortcircuiting the win ings of a singlephase repulsion motor to automatically convert it, at the desired speed, into an induction motor.

Among the objects of my invention are to produce an inexpensive, compact, selfcontained unit for the purpose mentioned which may be adjusted for the correct speed before attaching it to the motor and one capable of easy removal as a unit for replacement or repair should such be necessary. Other objects and advantages of my invention will appear from the following more detailed description.

` In the accompanying drawings, Fig. 1 is a rear elevational view of a shortcircuiting mechanism embodying my invention; Fig. 2 is a cross sectional view along the line 2 2 of Fig. 1; Fig. 3 is a side view; Figs. 4 and 5 are front views with the contact, disk removed, Fig. 4 showing the centrifugally actuated weights in their retracted position and Fig. 5 1n their extended position; Fig. 6 is cross section on the line 6-6 of Fig. 4; Fig. 7 is a rear view of the contact disk and parts permanently attached thereto; and Fig. 8 shows the mechanism applied to a motor.

In the form illustrated in-the drawings, my improved circuit closing mechanism comprises a supporting plate 1 attached to a collar 2 which collar makes a press lit with the motor shaft 3. Surrounding this collar and in fixed relation therewith is a sleeve 4 which constitutes a guide and support for the collar 5 which carriesthe shortcircuiting disk 6. This collar 5 fits loosely on the sleeve 4 and through the collar extend pins 7. The inwardly extending portions of these pins en age with oblique slots 8 in the sleeve 4 where y rotation of the collar 5 will cause a longitudinal shifting of the collar with respect to the sleeve.

The support 1 carries flat weights 9 and 10, weight 9 being pivoted on pin 11 and weight 10 on pin 12. Each of these ins extends through al slot in the free en of the weight for which it does not form the pivot, and they are provided with collars as shown, which retain the weights in the desired plane of movement. To each weight is connected a sprin as shown, which tends to hold the weight in retracted position as in Fig. 4. Turned upflanges 13 on the ends of the wei ht are provided with open ended slots 14 t rough which the outwardly extending ends of pin 7 project -when the shortcircuiting unit is in assembled relation.

Referring to Fig. 8 the commutator 15 has the usual horizontal surface with which brushes 16 contact and is provided with'a vertical contacting surface with which the resilientcontacting fingers 17 of the contact disk 6 are adapted to engage.-

The relation between the weights and springs being such so that centrifugal force acting upon the weights will overcome the spring tension and cause the weights to fly outwardly to the position indicated in Fig. 5 at the desired rotor speed, the motion of the weights, by reason of their connection with the collar 5, through pins 7, will cause this collar to rotate and since the collar has pin connection with the spiral slots in the sleeve 4, a longitudinal shifting of the collar 5 and attached disk 6 will simultaneously occur and the contact fingers of the ,disk 6 will be brought into contact with the ends of the commutator segments with a combined rotary and longitudinal motion. The parts are so positioned that a portion 'of the rotary movement of the disk occurs after initial contacting of the fingers 17 with the commutatorl segments, these fingers being somewhat resilient, and a wiping contact between disk andwsegments is thereby brought about. y

As previously stated, a loose fit is rovided between collar 5 and sleeve 4 W ich permits suicient tilting to allow properl ,seating of the disk a ainst the vertical face of the commutator, t'" due to the action of the springs on the weights, which action applying it to the motor. .The contacting disk may likewise be removed and a new one substituted without removing any other part of vthe mechanism. The removal of this disk also permits convenient access to the spring supports for replacement Aor adjustment of springs. Thus, since the contact disks and the springs are the only parts which might requirereplacement as the result of wear, it will be appfarent that my improved mechanism has the advantage of lov:T maintenance cost and capability of being repaired by the most inexpert mechanic.

I prefer to make at least the sleeve 4 of vbrass or other non-rusting metal whereby there is no danger of rust interfering with the motion of the contacting disk.

' I am aware that modications may be made in the construction herein described without departing from the essential principles of the invention and I therefore do not intend .that its scope be limited to the particular details of the mechanism shown, nor to the particular application described since the mechanism is adapted to eiect circuit changing operations in various kinds ofdynamo electric machines.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A dynamo electric machine having a member mounted on the rotor shaft to rober, va circuit closing member carried by said sleeve and capable of rotary and sliding motion with respect thereto, one of said last lnamed parts being provided with an oblique slot and the other with a pin operating in said slot, a weight carried by the member mounted on the motor shaft provided with a slotted extension engaging with a portion of the circuit closing member.

2. Circuit changing mechanism for a dynamo electric machine, comprising a sleeve, a contact member mounted thereon, a movable weight, and pin and slot connections between the sleeve and 'contact member and between the contact member and weight, said slots having open ends so located when weight is in extended position that the contact member may be withdrawn from connection with sleeve and weight.

3. Circuit changing mechanism for adynamo electric machine, comprising a sleeve, a contact member mounted thereon, a movable weight, and pin and slot connections between the sleeve and contact member and between the contact member and weight,

said slots having o en ends so located when Weight is in exten ed position that the contact member may be withdrawn from connection with sleeve and weight, and resilient means tending to hold the slots outof lthe disassembling relation described.

4. In a dynamo electric machine provided with a commutator having a vertical face, a circuit closing disk supported for sliding motion into contact with thecommutator, and capable of tilting withresp'ect to its support to adjust itselfto the commutator face, means to prevent tilting of the disk when it is in retracted position, and centrifugal means for actuating the disk.

In testimony whereof, I have hereunto set my hand and affixed my seal.

' .CARL H. WoLFF., [a 5;]

tate therewith, a sleeve carried by said mem- 

